Volume 14,Issue 3,2016 Table of Contents
2016, 14(3):1-6.
Abstract:
In this study, a distributed water resources allocation model is developed, systematically represents the natural-artificial water cycle. The model couples the hydrological and accompanying processes with the water allocation process through “online” or “offline”, and then the water allocation is simulated with rule ensembles based on abstract rule framework, which forms a common water resources allocation model considering the hydrological, water quality, ecological and water resources. The model can be well used under different rules, which realizes integrated water resources allocation considering the water quantities, qualities and ecological requirement. Then the model is used for a case study, the model can provide reasonable results for water resources allocation by adjusting rules according the water supply and demand.
In this study, a distributed water resources allocation model is developed, systematically represents the natural-artificial water cycle. The model couples the hydrological and accompanying processes with the water allocation process through “online” or “offline”, and then the water allocation is simulated with rule ensembles based on abstract rule framework, which forms a common water resources allocation model considering the hydrological, water quality, ecological and water resources. The model can be well used under different rules, which realizes integrated water resources allocation considering the water quantities, qualities and ecological requirement. Then the model is used for a case study, the model can provide reasonable results for water resources allocation by adjusting rules according the water supply and demand.
2016, 14(3):7-11.
Abstract:
In this paper, we developed a remote sensing driven distributed water balance and water transport model (RSWB/WTM) based on WBM/WTM(Water balance model/Water transport model) model. Using precipitation and evaportranspiration data retrieved from remote sensing, the monthly discharge of three hydrological stations (Fuping, Zhongtangmei and Zijingguan) in Baiyangdian Region was simulated. Then the accuracy of the model was evaluated using Nash and Sutcliffe model efficiency coefficients (E (NS)) and R2. The E (NS) for all stations were above 0.54, among which Zhongtangmai and Zijingguan were larger than 0.62. The R2 were 0.56, 0.64 and 0.64 for Fuping, Zhongtangmei and Zijingguan, respectively. In recent years, human activities had affected the natural water balance in Baiyangdian largely, thus the accuracy of the model was much influenced. It is also affected by the quality of the remote sensing retrieved data. It is hoped that our RSWB/WTM model and its application in Baiyangdian Region can provide a useful tool for the water resource assessment based on remote sensing data.
In this paper, we developed a remote sensing driven distributed water balance and water transport model (RSWB/WTM) based on WBM/WTM(Water balance model/Water transport model) model. Using precipitation and evaportranspiration data retrieved from remote sensing, the monthly discharge of three hydrological stations (Fuping, Zhongtangmei and Zijingguan) in Baiyangdian Region was simulated. Then the accuracy of the model was evaluated using Nash and Sutcliffe model efficiency coefficients (E (NS)) and R2. The E (NS) for all stations were above 0.54, among which Zhongtangmai and Zijingguan were larger than 0.62. The R2 were 0.56, 0.64 and 0.64 for Fuping, Zhongtangmei and Zijingguan, respectively. In recent years, human activities had affected the natural water balance in Baiyangdian largely, thus the accuracy of the model was much influenced. It is also affected by the quality of the remote sensing retrieved data. It is hoped that our RSWB/WTM model and its application in Baiyangdian Region can provide a useful tool for the water resource assessment based on remote sensing data.
2016, 14(3):12-16.
Abstract:
Jiagedaqi District of Greater Khingan Range area in Heilongjiang Province, located in the northeastern part of China, belongs to the typical high altitude cold regions, and is one of the most serious groundwater overflow icing problem areas in China. Located in the east area of Jiagedaqi, East River is a representative area of the regional overflow icing phenomenon. With the methods of field reconnaissance survey and hydrogeological exploration, this article not only analyzed the three formation stages and characteristics of the overflow icing phenomenon in the region, especially the meteorology, watershed underlying surface and frozen layer on the influence of the phenomenon, but also pointed out that the shallow aquifer in the watershed underlying surface factor and frozen layer of Jiagedaqi District were key influencing factors to form the unique overflow icing phenomenon in the region.
Jiagedaqi District of Greater Khingan Range area in Heilongjiang Province, located in the northeastern part of China, belongs to the typical high altitude cold regions, and is one of the most serious groundwater overflow icing problem areas in China. Located in the east area of Jiagedaqi, East River is a representative area of the regional overflow icing phenomenon. With the methods of field reconnaissance survey and hydrogeological exploration, this article not only analyzed the three formation stages and characteristics of the overflow icing phenomenon in the region, especially the meteorology, watershed underlying surface and frozen layer on the influence of the phenomenon, but also pointed out that the shallow aquifer in the watershed underlying surface factor and frozen layer of Jiagedaqi District were key influencing factors to form the unique overflow icing phenomenon in the region.
2016, 14(3):17-23.
Abstract:
In recent years, the global change has become a hot topic at home and abroad, the temperature and precipitation play the vital role in the climate change. Henan Province is the important grain base of China, and studying the temporal and spatial variation characteristics of the temperature and precipitation has a profound guiding for the agricultural production., The annual and seasonal changes of the temperature and precipitation in Henan Province from 1961 to 2014 were analyzed using the linear regression method，cumulative anomaly method，and M-K test method. The results indicated that, in recent 54 years, the annual mean temperature rose significantly, increasing by 0.18℃/10a; except in summer，the seasonal mean temperatures of the rest seasons showed increasing trends; and an abrupt change from low to high occurred in 1993-1994. The plain regions had warmed at a faster rate than the hilly area. The annual precipitation showed a subtle decreasing trend in recent 54 years, decreasing by -7.26mm/10a; the decreasing season was spring and autumn and the increasing season was summer and winter, and the abrupt change of precipitation occurred in 2011-2012. The precipitation increased significantly in the eastern plain area and decreased significantly in the area of mountain in the northwest and south as well as the west of Nanyang.
In recent years, the global change has become a hot topic at home and abroad, the temperature and precipitation play the vital role in the climate change. Henan Province is the important grain base of China, and studying the temporal and spatial variation characteristics of the temperature and precipitation has a profound guiding for the agricultural production., The annual and seasonal changes of the temperature and precipitation in Henan Province from 1961 to 2014 were analyzed using the linear regression method，cumulative anomaly method，and M-K test method. The results indicated that, in recent 54 years, the annual mean temperature rose significantly, increasing by 0.18℃/10a; except in summer，the seasonal mean temperatures of the rest seasons showed increasing trends; and an abrupt change from low to high occurred in 1993-1994. The plain regions had warmed at a faster rate than the hilly area. The annual precipitation showed a subtle decreasing trend in recent 54 years, decreasing by -7.26mm/10a; the decreasing season was spring and autumn and the increasing season was summer and winter, and the abrupt change of precipitation occurred in 2011-2012. The precipitation increased significantly in the eastern plain area and decreased significantly in the area of mountain in the northwest and south as well as the west of Nanyang.
2016, 14(3):24-29.
Abstract:
A statistical downscaling model that based on the stepwise-cluster analysis(SCADS), was employed to establish a statistical downscaling relationship between the large-scale climate variables from the multi-ensemble GCMs, and the regional climate variables of the Kaidu River basin, as well as to calculate the prediction of climate change in the future. The results indicated that the outputs of SCADS could model the climate variables of Kaidu River basin with a satisfactory. The NSE for all climate variables in the calibration (1961-1990) and validation (1991-1999) periods were larger than 0.55, indicating a good precision of SCADS. Besides, in terms of the prediction of climate change in the future of Kaidu River basin, it was shown an upwards of monthly average temperature, and a larger amount of evaporation, precipitation, sunshine-hour, and relative-humidity in three different periods (2011-2040, 2041-2070 and 2071-2100).
A statistical downscaling model that based on the stepwise-cluster analysis(SCADS), was employed to establish a statistical downscaling relationship between the large-scale climate variables from the multi-ensemble GCMs, and the regional climate variables of the Kaidu River basin, as well as to calculate the prediction of climate change in the future. The results indicated that the outputs of SCADS could model the climate variables of Kaidu River basin with a satisfactory. The NSE for all climate variables in the calibration (1961-1990) and validation (1991-1999) periods were larger than 0.55, indicating a good precision of SCADS. Besides, in terms of the prediction of climate change in the future of Kaidu River basin, it was shown an upwards of monthly average temperature, and a larger amount of evaporation, precipitation, sunshine-hour, and relative-humidity in three different periods (2011-2040, 2041-2070 and 2071-2100).
2016, 14(3):30-35.
Abstract:
Based on the observed data of precipitation from 1951 to 2013 in Xi’an city, its precipitation characteristics were analyzed using anomaly, accumulated anomaly and Mann-Kendall test method, and then annual precipitation was simulated and predicted by BP neural network. The results showed that annual precipitation of Xi’an city was descending, but the trend was insignificant (confidence level was 95%), all seasons presented descending except summer which showed a slight increasing trend, and precipitation in spring had a significant declining trend (confidence level was 95%). The abrupt change of annual precipitation occurred in 1965. The forecasting results by BP neural network showed that annual precipitations of 2014 and 2016 were abundant and 2015 was low. The research has certain significance for guiding scientific and rational use of precipitation resource.
Based on the observed data of precipitation from 1951 to 2013 in Xi’an city, its precipitation characteristics were analyzed using anomaly, accumulated anomaly and Mann-Kendall test method, and then annual precipitation was simulated and predicted by BP neural network. The results showed that annual precipitation of Xi’an city was descending, but the trend was insignificant (confidence level was 95%), all seasons presented descending except summer which showed a slight increasing trend, and precipitation in spring had a significant declining trend (confidence level was 95%). The abrupt change of annual precipitation occurred in 1965. The forecasting results by BP neural network showed that annual precipitations of 2014 and 2016 were abundant and 2015 was low. The research has certain significance for guiding scientific and rational use of precipitation resource.
2016, 14(3):36-42.
Abstract:
The annual precipitation time series of 20 climate stations in the northern part of Haihe River Basin from 1956 to 2012 were analyzed in this paper. The spatial and multi-temporal characteristics of the rainfall were analyzed from the aspects of trend test, period analysis, breakpoint detection and spatial heterogeneity analysis. The results showed that: (1) the rainfall of the northern part of Haihe River Basin decreased by 14.9mm per ten years; (2) rainfall of different time scales had significantly different characters: the monthly rainfall was steady, with rainfall in October and November decreasing significantly and that in May and June increasing significantly; the rainfall in spring and autumn were relatively stable and the decline in summer and winter were of significance; the annual rainfall were of 28 years period and switched from wet season to dry season in around 1980s. (3) annual rainfall in mountain areas reduced at a rate twice as quick as that in plain areas, but had more solid period and earlier breakpoint.
The annual precipitation time series of 20 climate stations in the northern part of Haihe River Basin from 1956 to 2012 were analyzed in this paper. The spatial and multi-temporal characteristics of the rainfall were analyzed from the aspects of trend test, period analysis, breakpoint detection and spatial heterogeneity analysis. The results showed that: (1) the rainfall of the northern part of Haihe River Basin decreased by 14.9mm per ten years; (2) rainfall of different time scales had significantly different characters: the monthly rainfall was steady, with rainfall in October and November decreasing significantly and that in May and June increasing significantly; the rainfall in spring and autumn were relatively stable and the decline in summer and winter were of significance; the annual rainfall were of 28 years period and switched from wet season to dry season in around 1980s. (3) annual rainfall in mountain areas reduced at a rate twice as quick as that in plain areas, but had more solid period and earlier breakpoint.
2016, 14(3):43-47.
Abstract:
With linear regression method, the accumulative anomaly curve method, Mann-Kendall trend and mutation test, spatial and temporal characteristics of precipitation variation are analyzed by using precipitation data of 25representative stations in Huaihe River Basin during 1960-2010. The results indicate that a slight increase in annual precipitations of Huaihe River Basin generally, but a decrease trend was maintained all the time during intermediate years and mutation starting year is 1965; On a spatial scale, the precipitation decreased gradually from south to north in Huaihe River basin. Upstream and midstream mostly show an ascendant trend, and downstream almost presents an increasing trend. The precipitation trend and mutation characteristics on space and time are analyzed, which provide the reference for the flood disaster prevention in Huaihe River basin.
With linear regression method, the accumulative anomaly curve method, Mann-Kendall trend and mutation test, spatial and temporal characteristics of precipitation variation are analyzed by using precipitation data of 25representative stations in Huaihe River Basin during 1960-2010. The results indicate that a slight increase in annual precipitations of Huaihe River Basin generally, but a decrease trend was maintained all the time during intermediate years and mutation starting year is 1965; On a spatial scale, the precipitation decreased gradually from south to north in Huaihe River basin. Upstream and midstream mostly show an ascendant trend, and downstream almost presents an increasing trend. The precipitation trend and mutation characteristics on space and time are analyzed, which provide the reference for the flood disaster prevention in Huaihe River basin.
2016, 14(3):48-54.
Abstract:
Focusing on a certain peninsula in Dalian where petrochemical accidents occur frequently, this research paper illustrates its current regional water environment contamination through the assessment of its groundwater’s quality. Additionally, with establishment of contamination prediction model applied to the area where the water resources that residents use have been polluted, this research predicts temporal and spatial change of petroleum pollutants and its effect on groundwater environment and adjacent sea area. The research results indicate that the polluted groundwater in consequence of the accidents of oil leakage have following features: the polluted area is comparatively large; the duration of pollution is long; the situation of pollution is serious. The pollutants in that site will remove to the sea area in 35 years according to the simulation results, which endangers the marine ecological environment. Above all, the results of this research provide bases for water environment conservation of this area.
Focusing on a certain peninsula in Dalian where petrochemical accidents occur frequently, this research paper illustrates its current regional water environment contamination through the assessment of its groundwater’s quality. Additionally, with establishment of contamination prediction model applied to the area where the water resources that residents use have been polluted, this research predicts temporal and spatial change of petroleum pollutants and its effect on groundwater environment and adjacent sea area. The research results indicate that the polluted groundwater in consequence of the accidents of oil leakage have following features: the polluted area is comparatively large; the duration of pollution is long; the situation of pollution is serious. The pollutants in that site will remove to the sea area in 35 years according to the simulation results, which endangers the marine ecological environment. Above all, the results of this research provide bases for water environment conservation of this area.
2016, 14(3):55-61.
Abstract:
The pattern of brine mainly distributed on upper aquifer and freshwater retained in the deeper sediments prevailing existed in the Hengshui district. Being excessive exploitation, the deeper freshwater trend to be salty induced by the shallow brine downward mitigation. A typical profile of domain is selected to investigate groundwater chemical characteristics variation, and its corresponding evolution mechanisms is analyzed via the data of water level, chemistry changes and groundwater pumping during 2011-2014. The results show that, the shallow aquifer shows a weak runoff in the horizontal direction; the shallow groundwater has a behavior of diverse chemical distribution with water quality improved from west to east among which ion concentration fluctuated significantly in the west. Reversely, horizontal runoff of deeper aquifer is strengthened affected by human excessive exploitation. There is a tendency to deteriorate in deep water though a better water quality remained nowadays. Hydrodynamic between adjacent aquifers is enhanced by pumping activities. There are some correlations of ion content between them and water seep from irrigation takes major accounts of recharge. Thereby, the deep freshwater is getting worse with interface of downward saline water.
The pattern of brine mainly distributed on upper aquifer and freshwater retained in the deeper sediments prevailing existed in the Hengshui district. Being excessive exploitation, the deeper freshwater trend to be salty induced by the shallow brine downward mitigation. A typical profile of domain is selected to investigate groundwater chemical characteristics variation, and its corresponding evolution mechanisms is analyzed via the data of water level, chemistry changes and groundwater pumping during 2011-2014. The results show that, the shallow aquifer shows a weak runoff in the horizontal direction; the shallow groundwater has a behavior of diverse chemical distribution with water quality improved from west to east among which ion concentration fluctuated significantly in the west. Reversely, horizontal runoff of deeper aquifer is strengthened affected by human excessive exploitation. There is a tendency to deteriorate in deep water though a better water quality remained nowadays. Hydrodynamic between adjacent aquifers is enhanced by pumping activities. There are some correlations of ion content between them and water seep from irrigation takes major accounts of recharge. Thereby, the deep freshwater is getting worse with interface of downward saline water.
2016, 14(3):62-66.
Abstract:
With the yearly decreasing discharge into sea and the increasing contradiction between the water resources supply and demand in urban area, the amount of discharges can not meet the ecological water demand of Tianjin coastal estuaries. As a result, it is very necessary to develop unconventional water compensation to ecological water for coastal estuaries. In this paper, unconventional water resources in Tianjin were surveyed, which included seawater, rainwater and reuse water. Combined with the utilization ways of unconventional water resources in Tianjin, the water amount which could be used for supplying ecological water to coastal estuaries was estimated. The results showed that the amount of rainwater and reuse water could absolutely meet the ecological water demand of coastal estuaries. And measures for ecological water supplement in coastal estuary were put forward. This research will provide technical reference for the effective development and utilization of unconventional water in Tianjin as well as effective supplement of ecological water for coastal estuaries.
With the yearly decreasing discharge into sea and the increasing contradiction between the water resources supply and demand in urban area, the amount of discharges can not meet the ecological water demand of Tianjin coastal estuaries. As a result, it is very necessary to develop unconventional water compensation to ecological water for coastal estuaries. In this paper, unconventional water resources in Tianjin were surveyed, which included seawater, rainwater and reuse water. Combined with the utilization ways of unconventional water resources in Tianjin, the water amount which could be used for supplying ecological water to coastal estuaries was estimated. The results showed that the amount of rainwater and reuse water could absolutely meet the ecological water demand of coastal estuaries. And measures for ecological water supplement in coastal estuary were put forward. This research will provide technical reference for the effective development and utilization of unconventional water in Tianjin as well as effective supplement of ecological water for coastal estuaries.
2016, 14(3):67-72.
Abstract:
The water source of Geermu which was in inland arid region was imbalance. With the gradual enlargement of the scale of Geermu water source mining, regional underground water level was decreased, and the overflow downstream was reduce, leading to vegetation degradation of oasis. Geermu River’s alluvial and flood fan hydrogeologic conditions were analyzed in this article. Visual Modflow was used to build a model on groundwater, aiming at impact prediction on oasis band downstream with decreasing of regional underground water level after the expansion of the gradual enlargement of the scale of Qingxia water source upstream in decades. The results showed that the oasis species were not affected by expanding mining, and the distribution of sedge would extend while soil salt content was suitable in wet season. The above results were standstill in normal water period and contrary in dry season.
The water source of Geermu which was in inland arid region was imbalance. With the gradual enlargement of the scale of Geermu water source mining, regional underground water level was decreased, and the overflow downstream was reduce, leading to vegetation degradation of oasis. Geermu River’s alluvial and flood fan hydrogeologic conditions were analyzed in this article. Visual Modflow was used to build a model on groundwater, aiming at impact prediction on oasis band downstream with decreasing of regional underground water level after the expansion of the gradual enlargement of the scale of Qingxia water source upstream in decades. The results showed that the oasis species were not affected by expanding mining, and the distribution of sedge would extend while soil salt content was suitable in wet season. The above results were standstill in normal water period and contrary in dry season.
2016, 14(3):73-77.
Abstract:
The grid-based Xinanjiang model was coupled with the Universal Soil Loss Equation to simulate water -sediment in the upstream of the Huaihe River.Based on the coupled model and DEM data, land use data, soil data and hydrological data of Xixian station during 2000-2010 years, the soil erosion in the upstream of the Huaihe River was simulated, and by setting two land-use patterns scenarios, the effect of different land use scenarios on soil erosion in the study area was quantitative analyzed. The results showed that the grid-based water - sediment coupled model had a better simulation accuracy in the upstream of the Huaihe River, the relative error of the simulated sediment load was less than 15%, and the uncertainty factor was above 0.6, which could meet the requirements of the sediment simulation accuracy. The woodland area was increased by 5%, then the amount of soil erosion of the basin was decreased by 8.78%, while an increase of 8% to urban, the soil erosion of the basin was decreased by 12.73%. The outputs can provide a reference value to soil and water conservation protecting in the upstream of the Huaihe River.
The grid-based Xinanjiang model was coupled with the Universal Soil Loss Equation to simulate water -sediment in the upstream of the Huaihe River.Based on the coupled model and DEM data, land use data, soil data and hydrological data of Xixian station during 2000-2010 years, the soil erosion in the upstream of the Huaihe River was simulated, and by setting two land-use patterns scenarios, the effect of different land use scenarios on soil erosion in the study area was quantitative analyzed. The results showed that the grid-based water - sediment coupled model had a better simulation accuracy in the upstream of the Huaihe River, the relative error of the simulated sediment load was less than 15%, and the uncertainty factor was above 0.6, which could meet the requirements of the sediment simulation accuracy. The woodland area was increased by 5%, then the amount of soil erosion of the basin was decreased by 8.78%, while an increase of 8% to urban, the soil erosion of the basin was decreased by 12.73%. The outputs can provide a reference value to soil and water conservation protecting in the upstream of the Huaihe River.
2016, 14(3):78-83.
Abstract:
The contaminant seepage problem of tailing-dam is an important factor affecting the safety of ground water of the tailing-dam, so accurately understanding the rules of the tailing-dam seepage and contaminant transportation in the tailings is great significance to the prevention of groundwater pollution. According to the seepage theory and the conditions of steep valley, large elevation difference, and tilted aquifer, a hydrogeological generalized model of tailing-dam based on horizontal multilayer subdivision was established，while Visual Modflow (MT3DMS) was used to analyze the transportation characteristics of ammonia nitrogen in the groundwater in the study area. The results indicated that ammonia nitrogen migration direction was consistent with groundwater flow direction, and ammonia nitrogen concentration decreased with the increase of the migration distance.
The contaminant seepage problem of tailing-dam is an important factor affecting the safety of ground water of the tailing-dam, so accurately understanding the rules of the tailing-dam seepage and contaminant transportation in the tailings is great significance to the prevention of groundwater pollution. According to the seepage theory and the conditions of steep valley, large elevation difference, and tilted aquifer, a hydrogeological generalized model of tailing-dam based on horizontal multilayer subdivision was established，while Visual Modflow (MT3DMS) was used to analyze the transportation characteristics of ammonia nitrogen in the groundwater in the study area. The results indicated that ammonia nitrogen migration direction was consistent with groundwater flow direction, and ammonia nitrogen concentration decreased with the increase of the migration distance.
2016, 14(3):84-89.
Abstract:
In order to investigate hydraulic characteristics of open channel flow, based on indoor experiments, rectangle open channel with different slope rates were used, and the conditions of the side walls, slope angle and flux were changed to obtain experiment data. The experimental results showed that: under the same condition, the water depth increased linearly with the increase of flow rate, and the average flow velocity and the Reynolds number increased with the increase of the flow rate. The Froude number increased with the increase of the flow rate when Fr＜1. With the increase of the flow rate, the Froude number increased and then decreased when 1＜Fr＜1.526，and decreased gradually when Fr＞1.526. The Manning roughness coefficient decreased with the increase of flow rate. In the case of the same condition and the same flow rate, with the increase of slope, the water depth decreased, and the average flow velocity, Reynolds number，Froude number and Manning roughness coefficient increased. The empirical formula of Reynolds number and gradient and flow rate was obtained by the experimental data.
In order to investigate hydraulic characteristics of open channel flow, based on indoor experiments, rectangle open channel with different slope rates were used, and the conditions of the side walls, slope angle and flux were changed to obtain experiment data. The experimental results showed that: under the same condition, the water depth increased linearly with the increase of flow rate, and the average flow velocity and the Reynolds number increased with the increase of the flow rate. The Froude number increased with the increase of the flow rate when Fr＜1. With the increase of the flow rate, the Froude number increased and then decreased when 1＜Fr＜1.526，and decreased gradually when Fr＞1.526. The Manning roughness coefficient decreased with the increase of flow rate. In the case of the same condition and the same flow rate, with the increase of slope, the water depth decreased, and the average flow velocity, Reynolds number，Froude number and Manning roughness coefficient increased. The empirical formula of Reynolds number and gradient and flow rate was obtained by the experimental data.
2016, 14(3):90-94.
Abstract:
The effects of suction on mechanical property of unsaturated remolding silt were investigated based on mean effective pressure and mean net pressure according to three kinds of stress paths with GDS apparatus. The results showed that preconsolidation pressure increased with suction based on mean effective pressure, and it was not obvious based on mean net pressure for isotropic compression test. The critical state line of unsaturated soils was not related to suction and was unique based on mean effective pressure, and it was paralleled to the critical state line of saturated soils and far away with suction increasing based on mean net pressure in undrained shear test.
The effects of suction on mechanical property of unsaturated remolding silt were investigated based on mean effective pressure and mean net pressure according to three kinds of stress paths with GDS apparatus. The results showed that preconsolidation pressure increased with suction based on mean effective pressure, and it was not obvious based on mean net pressure for isotropic compression test. The critical state line of unsaturated soils was not related to suction and was unique based on mean effective pressure, and it was paralleled to the critical state line of saturated soils and far away with suction increasing based on mean net pressure in undrained shear test.
2016, 14(3):101-105.
Abstract:
Based on Froude rule, test on a side-inlet pumping station model was conducted with increasing velocity of flow properly. The results showed that: the original scheme would cause a wide range of circulation in the surface layer and bottom layer of the forebay；the side flow deviated badly when the oblique flow get into the intake sump; it would cause sediment deposition easily if the velocity of flow in wing wall’s circulation area was too low. It was bad for safe and economic operation of the pump station. Several measures were used to regulate the flow pattern, including bottom sills, diversion walls, “Y” type diversion pier and “T” type diversion pier which was a variant from the “T” type. The flow pattern could be obtained best with “T” type diversion.
Based on Froude rule, test on a side-inlet pumping station model was conducted with increasing velocity of flow properly. The results showed that: the original scheme would cause a wide range of circulation in the surface layer and bottom layer of the forebay；the side flow deviated badly when the oblique flow get into the intake sump; it would cause sediment deposition easily if the velocity of flow in wing wall’s circulation area was too low. It was bad for safe and economic operation of the pump station. Several measures were used to regulate the flow pattern, including bottom sills, diversion walls, “Y” type diversion pier and “T” type diversion pier which was a variant from the “T” type. The flow pattern could be obtained best with “T” type diversion.
2016, 14(3):106-110.
Abstract:
Based on earthquake damage data collection around the world, the earthquake damage types of underground cavern were comprehensively analyzed, such as the structural failure caused by slope failure, the portal collapse, the fault movement of cavern crosscut, the large displacement between two intersected faults, the spalling of surrounding rock, the disturbance or deformation of the support and lining system and so on. Numerical simulation technology was applied to analyze the influencing factors of underground caverns destructiveness. The calculation results showed that: the cavern was easier to be destroyed under higher earthquake intensity; dynamic stability of circular tunnel was better; the cavern constructed on homogeneous and hard rock was nontrivial to been damaged by earthquake; the dynamic displacement response index would be smaller with a large ground stress in the underground cavern region; the increase of lining stiffness would partly rise the degree of the seismic damage ; the outlet of cavern suffered the earthquake destruction easily.
Based on earthquake damage data collection around the world, the earthquake damage types of underground cavern were comprehensively analyzed, such as the structural failure caused by slope failure, the portal collapse, the fault movement of cavern crosscut, the large displacement between two intersected faults, the spalling of surrounding rock, the disturbance or deformation of the support and lining system and so on. Numerical simulation technology was applied to analyze the influencing factors of underground caverns destructiveness. The calculation results showed that: the cavern was easier to be destroyed under higher earthquake intensity; dynamic stability of circular tunnel was better; the cavern constructed on homogeneous and hard rock was nontrivial to been damaged by earthquake; the dynamic displacement response index would be smaller with a large ground stress in the underground cavern region; the increase of lining stiffness would partly rise the degree of the seismic damage ; the outlet of cavern suffered the earthquake destruction easily.
2016, 14(3):111-114.
Abstract:
The microstructure and mineral composition of the expansive soil along Shiyan to Tianshui expressway in Longnan District were analyzed though scanning electron microscope (SEM) experiments and X-ray diffraction (XRD) experiments, and the expansion properties of expansive soil in this district were analyzed. According to the experiment results, the expansive soil particles basically presented as laminas with or without bending, which showed the properties of montmorillonite mineral particles or mixed-layer mineral particles of montmorillonite and illite; Lamelliform mineral particles were contacted surface to surface, and there were small gaps among the mineral particles; The mineral composition of this expansive soil was analyzed qualitatively and quantitatively, which showed small property of montmorillonite and large property of illite, kaolinite and quartz. Based on the experiment results above, the expansive soil along Shiyan to Tianshui expressway in Longnan legion of Gansu province was judged as weak expansive soil.
The microstructure and mineral composition of the expansive soil along Shiyan to Tianshui expressway in Longnan District were analyzed though scanning electron microscope (SEM) experiments and X-ray diffraction (XRD) experiments, and the expansion properties of expansive soil in this district were analyzed. According to the experiment results, the expansive soil particles basically presented as laminas with or without bending, which showed the properties of montmorillonite mineral particles or mixed-layer mineral particles of montmorillonite and illite; Lamelliform mineral particles were contacted surface to surface, and there were small gaps among the mineral particles; The mineral composition of this expansive soil was analyzed qualitatively and quantitatively, which showed small property of montmorillonite and large property of illite, kaolinite and quartz. Based on the experiment results above, the expansive soil along Shiyan to Tianshui expressway in Longnan legion of Gansu province was judged as weak expansive soil.
2016, 14(3):115-122.
Abstract:
Geographic Information System (GIS) is an important tool for hydrological geology research, and its application in hydrogeology field is one of the hot issues in groundwater research. The latest application of GIS to groundwater was introduced from seven aspects: groundwater resources evaluation, groundwater resources management, land subsidence, groundwater quality evaluation and pollutants analysis, hydrogeology survey, groundwater protection, and the combination of GIS and numerical simulation technology. At the same time, problems of GIS application in the field of hydrogeology were presented, and the development of GIS in hydrogeology field was discussed. In the future, what should be strengthened includes the integration of GIS and groundwater model and distributed hydrological model, the visualization of 3D or 4D groundwater system based on GIS, the application of web GIS technology and the establishment of comprehensive systems for water resources management and evaluation in a basin.
Geographic Information System (GIS) is an important tool for hydrological geology research, and its application in hydrogeology field is one of the hot issues in groundwater research. The latest application of GIS to groundwater was introduced from seven aspects: groundwater resources evaluation, groundwater resources management, land subsidence, groundwater quality evaluation and pollutants analysis, hydrogeology survey, groundwater protection, and the combination of GIS and numerical simulation technology. At the same time, problems of GIS application in the field of hydrogeology were presented, and the development of GIS in hydrogeology field was discussed. In the future, what should be strengthened includes the integration of GIS and groundwater model and distributed hydrological model, the visualization of 3D or 4D groundwater system based on GIS, the application of web GIS technology and the establishment of comprehensive systems for water resources management and evaluation in a basin.
2016, 14(3):123-131.
Abstract:
Correlation and multivariate statistical techniques were used to identify the natural hydrogeochemical processes and ventilation adit water-bursting source in the study area,. In the study area, water samples were of HCO3-Ca type. Three principal components were extracted. PC1 represented the ion exchange and the weathering of calcite, dolomite, and silicate minerals. PC2 and PC3 indicated hydrological processes, agricultural activities, and the process of evaporation, respectively. The hydrochemistry of water in the area had multiple factors, and natural mineral weathering and ion exchange were the most important ones. Cluster analysis of water samples were divided into four groups of clusters (Group1-Group4), and the water samples during wet and dry periods were compared and the degree of similarity between water samples were determined. The ventilation adit water samples M1 and M2 had great similarity with spring sample S3.
Correlation and multivariate statistical techniques were used to identify the natural hydrogeochemical processes and ventilation adit water-bursting source in the study area,. In the study area, water samples were of HCO3-Ca type. Three principal components were extracted. PC1 represented the ion exchange and the weathering of calcite, dolomite, and silicate minerals. PC2 and PC3 indicated hydrological processes, agricultural activities, and the process of evaporation, respectively. The hydrochemistry of water in the area had multiple factors, and natural mineral weathering and ion exchange were the most important ones. Cluster analysis of water samples were divided into four groups of clusters (Group1-Group4), and the water samples during wet and dry periods were compared and the degree of similarity between water samples were determined. The ventilation adit water samples M1 and M2 had great similarity with spring sample S3.
2016, 14(3):132-137.
Abstract:
The excessive exploitation of groundwater is the main cause of land subsidence in Tianjin. By analyzing the groundwater exploitation and land subsidence data from 1980 to 2013 of the central area of Tianjin, Tanggu, Hangu and Dagang District, the correlation model of the cumulative amount of land subsidence and groundwater exploitation was established. The results showed that the error was small when the model simulated the cumulative amount of land subsidence. On this basis, combined with the actual situation, 3 groundwater extraction plans were designed to forecast the regional land subsidence from 2014 to 2020. The results showed that the scheme 3 was the optimum groundwater exploitation scheme, the reduction ratios of the year settlement and cumulative settlement between scheme 3 and 1 were about 68.29% and 5.47%, and were 65.65% and 4.97 % between scheme 3 and 2. In addition, the rate of land subsidence would significantly reduce when the South to North Water Diversion Project was carried out.
The excessive exploitation of groundwater is the main cause of land subsidence in Tianjin. By analyzing the groundwater exploitation and land subsidence data from 1980 to 2013 of the central area of Tianjin, Tanggu, Hangu and Dagang District, the correlation model of the cumulative amount of land subsidence and groundwater exploitation was established. The results showed that the error was small when the model simulated the cumulative amount of land subsidence. On this basis, combined with the actual situation, 3 groundwater extraction plans were designed to forecast the regional land subsidence from 2014 to 2020. The results showed that the scheme 3 was the optimum groundwater exploitation scheme, the reduction ratios of the year settlement and cumulative settlement between scheme 3 and 1 were about 68.29% and 5.47%, and were 65.65% and 4.97 % between scheme 3 and 2. In addition, the rate of land subsidence would significantly reduce when the South to North Water Diversion Project was carried out.
2016, 14(3):138-143.
Abstract:
Slope stability judgment is one of the most important aspects of the project. Through the practical application of the principle of orthogonal design to further optimize the slope experiment scheme, six factors including the cohesion of C, internal friction angle , slope , slope height H, bulk density , and poisson's ratio , and related five levels were used in the experiment. Then the safety factor of slope was calculated by strength subtraction. At last, by mutation progression method in the cusp mutation theory, the slope stability was further judged and analyzed. It is found that the slope stability judged and analyzed by the safety factor which was calculated only based on the finite element strength reduction had some limitations, so it was of accuracy and practicability to comprehensively judge the slope stability based on cusp catastrophe theory and finite element strength reduction.
Slope stability judgment is one of the most important aspects of the project. Through the practical application of the principle of orthogonal design to further optimize the slope experiment scheme, six factors including the cohesion of C, internal friction angle , slope , slope height H, bulk density , and poisson's ratio , and related five levels were used in the experiment. Then the safety factor of slope was calculated by strength subtraction. At last, by mutation progression method in the cusp mutation theory, the slope stability was further judged and analyzed. It is found that the slope stability judged and analyzed by the safety factor which was calculated only based on the finite element strength reduction had some limitations, so it was of accuracy and practicability to comprehensively judge the slope stability based on cusp catastrophe theory and finite element strength reduction.
2016, 14(3):144-149.
Abstract:
A stepwise cumulative displacements curve is usually presented for these landslides in the Three Gorges Reservoir, under the condition of reservoir water fluctuation and rainfall, which means the deformation of the landslide in reservoir is a typical stepwise process. In order to understand the dynamic deformation mechanism, stability and deformation trend of stepwise landslides in the Three Gorges Reservoir, taking Baijiabao landslide as an example, this paper used the information of field geological survey and exploration, and monitoring data of more than ten years, analyzed the dynamic deformation characteristics, mechanism, influence factors and stability of Baijiabao landslide in detail, and predicted the deformation trend. The results showed that, due to the poor soil permeability of landslide body, the underground water in landslide could not be discharged in time during the drawdown of reservoir water, so the decline speed of groundwater was much slower than that of reservoir water, and then increasing the seepage force in the landslide body apparently, further reducing landslide stability. In addition, the faster the drawdown rate, the faster the movement of the landslide was.
A stepwise cumulative displacements curve is usually presented for these landslides in the Three Gorges Reservoir, under the condition of reservoir water fluctuation and rainfall, which means the deformation of the landslide in reservoir is a typical stepwise process. In order to understand the dynamic deformation mechanism, stability and deformation trend of stepwise landslides in the Three Gorges Reservoir, taking Baijiabao landslide as an example, this paper used the information of field geological survey and exploration, and monitoring data of more than ten years, analyzed the dynamic deformation characteristics, mechanism, influence factors and stability of Baijiabao landslide in detail, and predicted the deformation trend. The results showed that, due to the poor soil permeability of landslide body, the underground water in landslide could not be discharged in time during the drawdown of reservoir water, so the decline speed of groundwater was much slower than that of reservoir water, and then increasing the seepage force in the landslide body apparently, further reducing landslide stability. In addition, the faster the drawdown rate, the faster the movement of the landslide was.
2016, 14(3):150-155.
Abstract:
It is thought highly on feasibility and safety evaluation in karst region particularly in complex geological environmental conditions. In this article, a pumped storage power station in a karst area of Shaanxi province was taken as an example, karst development law and hydrodynamic condition of upper reservoir were analyzed, and a numerical simulation method was used to make fine description of space form of complex karst channel in reservoir, so as to predict potential karst leakage channel. The prediction results showed that three karst channels would be serious leakage after the completion of the reservoir, of which the maximum was “First day”, with the leakage of 4058.89m3/d, and the leakages of foundation and lodgepole pine beam were 3564.69m3/d and 3085.23m3/d respectively. However, the leakages of karst channels decreased obviously after being applied the impervious curtain measures.
It is thought highly on feasibility and safety evaluation in karst region particularly in complex geological environmental conditions. In this article, a pumped storage power station in a karst area of Shaanxi province was taken as an example, karst development law and hydrodynamic condition of upper reservoir were analyzed, and a numerical simulation method was used to make fine description of space form of complex karst channel in reservoir, so as to predict potential karst leakage channel. The prediction results showed that three karst channels would be serious leakage after the completion of the reservoir, of which the maximum was “First day”, with the leakage of 4058.89m3/d, and the leakages of foundation and lodgepole pine beam were 3564.69m3/d and 3085.23m3/d respectively. However, the leakages of karst channels decreased obviously after being applied the impervious curtain measures.
2016, 14(3):156-161.
Abstract:
Distribution of groundwater resources in Houtao plain is uneven with concentrated population and economy in the city and soil salinization caused by surface water flooding, which affected the social and economic sustainable development significantly. Therefore, a comprehensive evaluation of groundwater sustainability has become the prior task for regional planning. Groundwater sustainability reflects the groundwater utilization status directly, and is important for groundwater management. In this paper, the evaluation indexes were selected based on the problems caused by groundwater exploitation in Houtao plain, and the sustainability level of groundwater was evaluated using the comprehensive evaluation method. The results showed that groundwater sustainability varies in different areas. The areas with the worst groundwater sustainability are located in the south bank of the Yellow River and the northeast of the study area, and the areas with relatively better groundwater sustainability are located in the north and middle of the study area. The areas with good groundwater exploration potential are located in the north of Hangjinhouqi and Wuyuan County, whereas groundwater sustainability in most areas of Dengkou and Wulataqianqi County is low with serious desertification; therefore, water consumption industry should not to be developed in that area.
Distribution of groundwater resources in Houtao plain is uneven with concentrated population and economy in the city and soil salinization caused by surface water flooding, which affected the social and economic sustainable development significantly. Therefore, a comprehensive evaluation of groundwater sustainability has become the prior task for regional planning. Groundwater sustainability reflects the groundwater utilization status directly, and is important for groundwater management. In this paper, the evaluation indexes were selected based on the problems caused by groundwater exploitation in Houtao plain, and the sustainability level of groundwater was evaluated using the comprehensive evaluation method. The results showed that groundwater sustainability varies in different areas. The areas with the worst groundwater sustainability are located in the south bank of the Yellow River and the northeast of the study area, and the areas with relatively better groundwater sustainability are located in the north and middle of the study area. The areas with good groundwater exploration potential are located in the north of Hangjinhouqi and Wuyuan County, whereas groundwater sustainability in most areas of Dengkou and Wulataqianqi County is low with serious desertification; therefore, water consumption industry should not to be developed in that area.
2016, 14(3):162-168.
Abstract:
Water security is related to the vital interests of the masses, and has great influences on country’s sustainable development. A water security comprehensive evaluation model was constructed in this paper. This model established an evaluation index system of water security, which included 4 levels, employed 3 criteria levels (water health security, water development security and water guarantee security) and had 48 indicators. With the entropy weight method, the weight of each index was determined. And the formula for water security index was also given in the model. Furthermore, using the macroscopical data from 2000 to 2014, this paper applied the water security evaluation model to assess the water security situation of China. The results showed that during the study period, water health security showed a fluctuant increasing trend, water development security presented a slowly rising trend and water guarantee security was improved at a rapid speed. However, it still did not reach the best standard of water security, and further efforts were still required to improve China’s water security.
Water security is related to the vital interests of the masses, and has great influences on country’s sustainable development. A water security comprehensive evaluation model was constructed in this paper. This model established an evaluation index system of water security, which included 4 levels, employed 3 criteria levels (water health security, water development security and water guarantee security) and had 48 indicators. With the entropy weight method, the weight of each index was determined. And the formula for water security index was also given in the model. Furthermore, using the macroscopical data from 2000 to 2014, this paper applied the water security evaluation model to assess the water security situation of China. The results showed that during the study period, water health security showed a fluctuant increasing trend, water development security presented a slowly rising trend and water guarantee security was improved at a rapid speed. However, it still did not reach the best standard of water security, and further efforts were still required to improve China’s water security.
2016, 14(3):169-174.
Abstract:
Irrigation area and the accurate information of its distribution are very important for the modern management of irrigation area，while the traditional way to get irrigated area cannot meet the present needs. Satellite remote sensing has provided a relatively inexpensive, accurate, rapid, large-scale, and effective way by which nationwide survey irrigated area can be repeated and distributed. In recent years, more and more satellite remote sensing data sources have provided, and data quality has improved. Using remote sensing technology in the modern management of the irrigation area is the trend of the future. This paper investigated the feasibility of monitoring the drought index of remote sensing for irrigation, and built a remote sensing monitoring model for irrigation area based on drought index difference threshold. Taking the Qinhan Irrigated Area in Ningxia Province as a research area, the application research of the model was carried out. The environmental mitigation satellite (HJ1A / 1BCCD) data were selected to calculate and analyze the distribution and change of the Perpendicular Drought Index (PDI) of the study area of. The difference threshold was 0.082 by on-the-spot investigation of local conditions. Then the first spring irrigation and its changes over time scales of irrigated area were calculated. Compared and verified with the ground monitoring and statistical data, the accuracy of result could reach above 75%. The paper provided a new approach for irrigation area monitoring.
Irrigation area and the accurate information of its distribution are very important for the modern management of irrigation area，while the traditional way to get irrigated area cannot meet the present needs. Satellite remote sensing has provided a relatively inexpensive, accurate, rapid, large-scale, and effective way by which nationwide survey irrigated area can be repeated and distributed. In recent years, more and more satellite remote sensing data sources have provided, and data quality has improved. Using remote sensing technology in the modern management of the irrigation area is the trend of the future. This paper investigated the feasibility of monitoring the drought index of remote sensing for irrigation, and built a remote sensing monitoring model for irrigation area based on drought index difference threshold. Taking the Qinhan Irrigated Area in Ningxia Province as a research area, the application research of the model was carried out. The environmental mitigation satellite (HJ1A / 1BCCD) data were selected to calculate and analyze the distribution and change of the Perpendicular Drought Index (PDI) of the study area of. The difference threshold was 0.082 by on-the-spot investigation of local conditions. Then the first spring irrigation and its changes over time scales of irrigated area were calculated. Compared and verified with the ground monitoring and statistical data, the accuracy of result could reach above 75%. The paper provided a new approach for irrigation area monitoring.
2016, 14(3):175-182.
Abstract:
According to the data of grain output from 1990 to 2007 in Anhui Huaibei Plain, tendency yields were got by wielding sliding average method, and the annual yield reduction rates caused by drought were obtained by output reductions. The bandwidth was optimized by means of cross-validation for the improvement of accuracy of the information diffusion method in the drought loss risk assessment, and the applicability of information diffusion method based on cross-validation for the P-III distribution population in terms of computer simulation was proved. On this basis, the assessment model of drought loss risk was established, and the probability distribution of yield reduction rates caused by drought was caculated with information diffusion. Meanwhile, the risk distribution of regional drought was analyzed. It was found that the model in this paper was built reasonably and appropriately by comparison with others, and provided a certain reference value for solving common small sample size problems in the drought risk assessment.
According to the data of grain output from 1990 to 2007 in Anhui Huaibei Plain, tendency yields were got by wielding sliding average method, and the annual yield reduction rates caused by drought were obtained by output reductions. The bandwidth was optimized by means of cross-validation for the improvement of accuracy of the information diffusion method in the drought loss risk assessment, and the applicability of information diffusion method based on cross-validation for the P-III distribution population in terms of computer simulation was proved. On this basis, the assessment model of drought loss risk was established, and the probability distribution of yield reduction rates caused by drought was caculated with information diffusion. Meanwhile, the risk distribution of regional drought was analyzed. It was found that the model in this paper was built reasonably and appropriately by comparison with others, and provided a certain reference value for solving common small sample size problems in the drought risk assessment.
2016, 14(3):183-187.
Abstract:
Rainwater pipeline network is an important part of urban drainage engineering system. Optimal reconstruction of the pipeline network scientifically and economically is the key to improving the capacity of its drainability and effectively relieving urban waterlogging disasters. In order to achieve this goal, a pipeline network optimal reconstruction model based on multi-objective optimization (NSGA-II) was established in this paper. There were three objective functions in this optimal reconstruction model including construction cost, drainability, and quantities. In addition, by invoking program source code, the paper realized automatically executing SWMM for hydraulics simulation. At last, the paper took a case for application whose results showed that this optimal reconstruction model could get feasible reconstruction plans and would have some referential value.
Rainwater pipeline network is an important part of urban drainage engineering system. Optimal reconstruction of the pipeline network scientifically and economically is the key to improving the capacity of its drainability and effectively relieving urban waterlogging disasters. In order to achieve this goal, a pipeline network optimal reconstruction model based on multi-objective optimization (NSGA-II) was established in this paper. There were three objective functions in this optimal reconstruction model including construction cost, drainability, and quantities. In addition, by invoking program source code, the paper realized automatically executing SWMM for hydraulics simulation. At last, the paper took a case for application whose results showed that this optimal reconstruction model could get feasible reconstruction plans and would have some referential value.
2016, 14(3):188-192.
Abstract:
Soil salinization or alkalization is a comprehensive problem involving agriculture, land and water resources, as well as a typical ecological environment problem. Saline and alkaline land is important land resources, which is valuable in potential for the development of agricultural industrialization. There are large areas of saline and alkaline land with surveys in Dingbian county of Shaanxi province. Combined three alkali and salt treating technology of water storage, salt reducing and sand sieving, the farmland, salt reducing project, irrigation project, and road and shelterbelts project were comprehensively designed. The most significant method was that by breaking though the traditional models using the principle of movement of water and its soil around and the mechanism of salt cycling drainage to build up the new management model of “replacing draining by storing, water and soil conservation and eco-harmony”. The results indicated that 746.32 hm2 land in all had been developed, in which 667.42 hm2 was plough. In this way, we find new ways to manage soil salinization or alkalization, increased the incomes and improved the eco-environment.
Soil salinization or alkalization is a comprehensive problem involving agriculture, land and water resources, as well as a typical ecological environment problem. Saline and alkaline land is important land resources, which is valuable in potential for the development of agricultural industrialization. There are large areas of saline and alkaline land with surveys in Dingbian county of Shaanxi province. Combined three alkali and salt treating technology of water storage, salt reducing and sand sieving, the farmland, salt reducing project, irrigation project, and road and shelterbelts project were comprehensively designed. The most significant method was that by breaking though the traditional models using the principle of movement of water and its soil around and the mechanism of salt cycling drainage to build up the new management model of “replacing draining by storing, water and soil conservation and eco-harmony”. The results indicated that 746.32 hm2 land in all had been developed, in which 667.42 hm2 was plough. In this way, we find new ways to manage soil salinization or alkalization, increased the incomes and improved the eco-environment.
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